A device to device proximity service (English full name: Device to Device Proximity Service, English abbreviation: D2D ProSe) between user equipment (English full name: User Equipment, English abbreviation: UE) has become a hot issue on a Long Term Evolution (English full name: Long Term Evolution, English abbreviation: LTE) system. Currently, a function of device to device (English full name: Device to Device, English abbreviation: D2D) communication has been applied to some existing cluster systems and some walkie-talkie devices. Because of a great success in commercialization of the LTE system, providing a D2D ProSe on the basis of a physical layer of the LTE system can not only enrich a service range of the LTE system, but also enable D2D communication to be used by more users.
Scrambling in the LTE system is mainly classified into two types: One type is data channel scrambling, which is used to scramble a data channel, and can implement interference randomization and user encryption; the other type is cyclic redundancy check (English full name: Cyclic Redundancy Check, English abbreviation: CRC) scrambling, which is used to scramble to-be-sent information after CRC, and can implicitly provide extra information and differentiate different users.
So far, there is no scrambling scheme for D2D communication. Therefore, in a process of performing D2D communication, how to scramble to-be-sent information at a transmit end and how to descramble received information at a receive end are problems to be resolved urgently.